• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1999년도 PROCEEDINGS OF 99 INTERNATIONAL CONFERENCE OF THE KACG AND 6TH KOREA·JAPAN EMG SYMPOSIUM (ELECTRONIC MATERIALS GROWTH SYMPOSIUM), HANYANG UNIVERSITY, SEOUL, 06월 09일 JUNE 1999
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• pp.129-157
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• 1999

Low-dislocation-density large-diameter GaAs single crystals with low-residual-strain have been strongly required. We have developed dislocation-free 3-inch Si-doped GaAs crystals for photonic devices [1], and low-dislocation-density low-residual-strain 4-inch to 6-inch [2, 3] semi-insulating GaAs crystals for electronic devices by Vertical Boat (VB) technique. We confirmed that VB substrates with low-residual-strain have higher resistance against slip-line generation during MBE process. VB-GaAs single crystals show uniform radial profile of resistivity reflecting to the flat solid-liquid interface during the crystal growth. Uniformity of micro-resistivity of VB-GaAs substrate is much better than that of the LEC-GaAs substrate, which is due to the low-dislocation-density of VB-GaAs single crystals.

• 대한치과의사협회지
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• 제17권5호통권120호
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• pp.345-350
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• 1979

The patient, 16 years female, complained of anterior cross-bite and retrusion of maxilla. Mandibular incisors occluded labially to maxillary incisors. Normally developed mandibular arch in normal elation to facial line, S-N-Pog was within normal range. Cross-bite of anterior teeth was corrected by means of Class III elastics under multibanded system. Space for alignment of crowding of upper anterior teeth was regained by means of cervical headgear and sliding yoke. She gained good alignment of anterior teeth and attractive facial profile after 2 years.

• 천문학회지
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• 제29권spc1호
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• pp.195-196
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• 1996

We observed CO J = 2 $\to$ 1 and J = 3 $\to$ 2 lines toward several star formation regions with extremely high velocity (EHV) outflows: W3 IRS5, W28 A2, GL2591, S140, and Cepheus A. The full width of the wings are 90-235 km $s^{-1}$. Some wings show clear break of slope in the line profile implying that the nature of the EHV outflow is different from that of the high velocity outflow. We suggest that the EHV CO wing emission is tracing CO molecules in the stellar wind or jet which drives the high velocity outflow.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1581-1584
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• 2003

This paper proposed efficient manufacturing system using OMM(on-machine measurement) system and OMM operating S/W based 3D modeler. A Developed program connected tool machine with RS232C. It is composed two operating system that touch probe operating and laser displacement sensor operating system. A program for touch probe possible measure considered inspection feature and CAD data. The laser operating program is used inspection for profile. very small hole using installed feature data. This system is applied manufacturing line of mold(cavity, core) also verification of efficiency manufacturing process that production, reduction machining error of each process

• 동력기계공학회지
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• 제3권2호
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• pp.13-19
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• 1999

The purpose of the present experimental study is to apply multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to high-speed flow region within a domestic boiler circulation pump. Two different kinds of flow rate($27{\ell}/min,\;19{\ell}/min$)are selected as experimental condition. A volute casing and Impeller made of transparent Polycarbonate were made for the easy access of the illumination laser via fiber optical line and cylinder lens assembly to the measuring region. A CCD camera is syncronized with AOM to acquire clear original particle images. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. The instantaneous and time-mean velocity distribution, velocity profile and kinetic energy are represented quantitatively at the full-scale region for the deeper understanding of the unsteady flow characteristics in a commercial circulation pump.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.323-327
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• 1995

A new air knife system for coating thickness control in hot dip galvanizing process had been developed and installed on the CGL in Pohang Steel Works, POSCO. This new system consists of air knives with remotely adjustable nozzle slot and an automatic control system which can control both longitudinal and traverse coating deviations. Based on the optimal control algorithm, a traverse coating deviation control was designed. The controller controls the lip profile of the air knives with flexible structure according to the deviation of coating weight. From the measured values which are dependent on the strip width, the lip gaps are calculated with optimal algorithm and the model of the coating deviation. Time delay between knives and a coating thickness gauge is solved by the Smith Predictor.

• 제어로봇시스템학회논문지
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• 제12권7호
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• pp.671-678
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• 2006

This article proposes a smooth path generation and time scheduling method for general tasks defined by non-smooth path segments in industrial robotic applications. This method utilizes a simple 3rd order polynomial function for smooth interpolation between non-smooth path segments, so that entire task can effectively maintain constant line speed of operation. A predictor-corrector type numerical mapping technique, which correlates time based speed profile to the smoothed path in Cartesian space, is also provided. Finally simulation results show the feasibility of the proposed algorithm.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(3)
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• pp.37-40
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• 2000

A fast method of Hangul address word verification is presented in this Paper. Pre-segmentation and recognition by DP matching is adopted in this paper. An address line image is over-segmented by analyzing the topology of connected components and the projection profile. A fast individual Hangul character verifier was developed by applying SVM (Support Vector Machine). The segmentation hypothesis was represented by lattice structure, and a best path search by dynamic programming generates the most probable segmentation path and the final verification score. The word verifier was tested on 310 address image DB, and it show the possibility of improvements of this method.

• 전자공학회논문지A
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• 제31A권7호
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• pp.69-75
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• 1994

A very fine pattern formation process using double exposure is investigated, which can overcome the resolution limit of optical wafer stepper. The very fine pattern can be obtained by moving the edge profile of large pattern by means of moving the stepper stage. The simulation results show that the light transmittance decrease bellow 9%, and the contrast increase to 16.6% for the 0.3$\mu$m photoresist pattern exposeed by the double exposure using i-line wafer stepper. And the experimental results show that fine photoresist pattern as short as 0.2$\mu$m can be obtained without a loss of photoresist thickness. Also, it proves that the depth of focus for 0.3$\mu$m pattern is longer than $1.5\mu$m. And, the very fine negative photoresist pattern was formmed by using the double exposure technique and the image reversal process.

• 전자공학회논문지D
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• 제34D권9호
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• pp.36-42
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• 1997

Optical filters with graded index profiles are designed by applying the fourier transform to a riccati equation which governs the reflection and transmission characteristics of inhomogeneous refractive index distributions. The inhomogeneous refractive index profile of an optical filter with specified target spectrum is obtained through iterations. The spectra response of the inhomogeneous refractive index layers are analyzed by using runge-dutta numerical method to solve the differential euations of the amplitude and the phase of reflection coefficient derived from the riccati equation and the results are in good agreement with the resutls obtained by using matrix method.